Catalyst

1. Balance the following reaction:

… C +… S8 … CS2

2. Reactants are on the ________side, products on the ________side. (left or right)

3. In the compound, 4H2O, what is the 4 telling you?

Today’s Agenda

5 min

• Catalyst

20 min

• Balancing Equations with Polyatomics

30 min

• Computer Practice

5 min

• Exit Slip

Remember…

Why do we have to balance chemical reactions?

Law of Conservation of Mass!

Balancing with a little extra…

What if you have some polyatomic ions, like (NO3)?

WHAT will you do??

When balancing equations that involve polyatomic ions, keep them together!

Work it out…

H3(PO4) + K(OH) K3(PO4) + H2O

Which polyatomics are we using? PO4- phosphate OH- hydroxide

Where is the OH on the other side? In the H2O! It can be written as HOH.

Balance It!

__H3(PO4) + __K(OH) __K3(PO4) + __H2O

Your turn

In your notes, try these problems:

1. …Na(OH) + …H2(CO3) …Na2(CO3) + …H2O

2. …Al(OH)3 + …H2(CO3) …Al2(CO3)3 +…H2O

Today’s Agenda

5 min

• Catalyst

20 min

• Balancing Equations with Polyatomics

30 min

• Computer Practice

5 min

• Exit Slip

Practice, Practice, Practice…

Check out this worksheet – you get to select your own “buffet”

The questions you complete must add up to 100 points

If you do more problems, you will receive extra credit

Today’s Agenda

5 min

• Catalyst

20 min

• Balancing Equations

30 min

• Practice

5 min

• Exit Slip

Exit Slip

1. Balance the following reaction:

__Ca + __HNO3 → __H2 + __Ca(NO3)2

2. __Ca(NO3)2 + __Na2S __CaS + __NaNO3

When the equation representing the reaction above is completed and balanced and all coefficients are reduced to lowest whole-number terms, the coefficient for NaNO3 is:

a. 1 b. 2 c. 3 d. 4